Background: Postoperative delirium is relatively common. However, the relationship between intravenous patient-controlled analgesia (IV-PCA) and delirium has not been thoroughly investigated. The aim of this study was to evaluate the effects of IV-PCA on the prognosis of postoperative delirium in patients undergoing orthopedic surgery. Methods: Medical records of 129 patients with postoperative delirium were reviewed. Patients were divided into two groups according to whether they used IV-PCA with fentanyl and ketorolac. The IV-PCA group consisted of 73 patients who were managed with IV-PCA; the NO-PCA group consisted of 56 patients who were managed without PCA. Results: Incidences of multiple psychiatric consultations and prolonged delirium were significantly lower in patients using IV-PCA with fentanyl and ketorolac than in those without PCA. Conclusions: We recommend the use of IV-PCA for pain control and management of delirium in patients with postoperative delirium.